Mirtazapine (Mirataz / Remeron)
A tetracyclic antidepressant that antagonizes central presynaptic alpha-2 and serotonin receptors, used as a powerful appetite stimulant.
💬 In Plain English
Mirtazapine is the premier prescription appetite stimulant used for sick dogs and cats that refuse to eat (anorexia). It works on the brain’s hunger center by blocking central alpha-2 adrenergic receptors and serotonin 5-HT2/5-HT3 receptors, which simultaneously triggers intense hunger and shuts off nausea. For cats suffering from kidney disease, cancer, or pancreatitis, mirtazapine is available as an innovative transdermal ear ointment (Mirataz): owners simply wipe a ribbon of ointment onto the hairless inner surface of the cat’s ear flap once daily with a gloved finger, stimulating their appetite without any pill-swallowing battles.
🔬 Clinical & Technical Depth
For Vets & TechniciansFormal Clinical Definition
Presynaptic alpha-2 adrenergic antagonist and serotonin (5-HT2 and 5-HT3) receptor antagonist that enhances noradrenergic and serotonergic neurotransmission to stimulate central appetite while suppressing vomiting.
Why Veterinarians Use It
Veterinarians prescribe mirtazapine to stimulate appetite and reverse life-threatening weight loss in cats with chronic kidney disease and dogs receiving chemotherapy.
Clinical Context Encountered
Prescribed as transdermal ear ointment (Mirataz) for cats or oral tablets for dogs and cats.
Clinical Reference Guide (Veterinary Medication)
What Owners Must Know
- Wear a disposable glove when applying to avoid human absorption
- Apply a 1.5-inch ribbon of ointment to the inside pinna of the ear daily, alternating ears
- Clean residual medication before next application.
Potential Side Effects
- Vocalization and hyperactivity
- Lethargy or sedation (dose-dependent)
- Contact erythema on inner pinna
- Serotonin syndrome if combined with MAOIs or SSRIs
- •Always wear disposable gloves when applying Mirataz transdermal ointment: human skin absorbs mirtazapine readily, causing drowsiness and dizziness.
❓ Questions to Ask Your Veterinarian
Take these actionable questions with you to your next clinic visit or appointment:
- 1Should I wear a glove or finger cot when applying transdermal Mirataz ointment to prevent absorbing it through my own skin?
- 2How should I alternate between the left and right inner ear flaps daily to avoid skin irritation?
- 3If my cat becomes overly vocal or agitated, should we decrease the dose or apply every other day?
Academic & Clinical References
- FDA CVM: Mirataz (mirtazapine transdermal ointment) Approval SummaryOrganization: U.S. Food and Drug Administration (FDA CVM) • Accessed: 2026-01-10https://www.fda.gov/animal-veterinary